The present invention relates to file access, and more specifically, this invention relates to performing lookups utilizing a virtual file system (VFS).
In predetermined operating systems (e.g., UNIX-like operating systems, etc.), when a file is accessed by a user for the first time the virtual file system (VFS) layer may go through each component of the file path and may construct dentry objects that tie the path components to the corresponding inodes. This procedure is called a lookup. Current lookup operations require multiple I/O requests to the underlying slow storage. E.g., to lookup “/tmp/foo/bar”, three or more I/O requests may be needed (one for every path component).
As a result, lookups are slow and the cost of lookup is a dominant cost for many file system instances. Current attempts to address these issues have high memory cost and expansion size limitations.